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  <font size="+3">&#8592;</font> <a href="https://hosseinmoein.github.io/DataFrame/docs/HTML/DataFrame.html">Back to Documentations</a><BR><BR>
  
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      <th>Signature</th> <th>Description</th> <th>Parameters</th>
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<pre class="code_syntax" style="color:#000000;background:#ffffff00;"><span class="line_wrapper"><span style="color:#004a43; ">#</span><span style="color:#004a43; ">include </span><span style="color:#800000; ">&lt;</span><span style="color:#40015a; ">DataFrame/DataFrameMLVisitors.h</span><span style="color:#800000; ">&gt;</span></span>
<span class="line_wrapper"></span>
<span class="line_wrapper"><span style="color:#800000; font-weight:bold; ">template</span><span style="color:#800080; ">&lt;</span><span style="color:#800000; font-weight:bold; ">typename</span> T<span style="color:#808030; ">,</span> <span style="color:#800000; font-weight:bold; ">typename</span> I <span style="color:#808030; ">=</span> <span style="color:#800000; font-weight:bold; ">unsigned</span> <span style="color:#800000; font-weight:bold; ">long</span><span style="color:#808030; ">,</span></span>
<span class="line_wrapper">         <span style="color:#666616; ">std</span><span style="color:#800080; ">::</span><span style="color:#603000; ">size_t</span> A <span style="color:#808030; ">=</span> <span style="color:#008c00; ">0</span><span style="color:#800080; ">&gt;</span></span>
<span class="line_wrapper"><span style="color:#800000; font-weight:bold; ">struct</span> DBSCANVisitor<span style="color:#800080; ">;</span></span>
<span class="line_wrapper"></span></pre>
      </td>
      <td>
        This is a single action visitor, meaning it is passed the whole data vector in one call and you must use the single_act_visit() interface.<BR><BR>

        Density-Based Spatial Clustering of Applications with Noise (DBSCAN) is a data clustering algorithm proposed by Martin Ester, Hans-Peter Kriegel, Jörg Sander, and Xiaowei Xu in 1996. It is a density-based clustering non-parametric algorithm: given a set of points in some space, it groups together points that are closely packed (points with many nearby neighbors), and marks as outliers points that lie alone in low-density regions (those whose nearest neighbors are too far away). DBSCAN is one of the most commonly used and cited clustering algorithms.<BR>
        The constructor takes 3 parameters<BR>
        <OL>
        <LI>Minimum number of datapoints to constitute a cluster</LI>
        <LI>The distance used to determine if a data point is in the same area as other data points</LI>
        <LI>A function to calculate distance between two data points of type T (with default)</LI>
        </OL>
        <I>
        <PRE>
  DBSCANVisitor(long min_mems,
                double max_dist,
                distance_func f = [](const T &x, const T &y) -> double {
                                      return ((x - y) * (x - y));
                                  })
        </PRE>
        </I>
        </LI>
        </OL>
        <I>get_results()</I> Returns a vector of vectors containing datapoint values of each cluster.<BR><BR>
        <I>get_clusters_idxs()</I> Returns a vector of vectors containing indices to datapoints of each cluster.<BR><BR>
        <I>get_noisey_idxs()</I> Returns a vector containing indices to datapoints that could not be placed in any cluster. Ideally you want this to be empty.<BR>
       </td>
      <td width="30%">
        <B>T</B>: Column data type<BR>
        <B>I</B>: Index type<BR>
        <B>A</B>: Memory alignment boundary for vectors. Default is system default alignment<BR>
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<pre class="code_syntax" style="color:#000000;background:#ffffff00;"><span class="line_wrapper"><span style="color:#800000; font-weight:bold; ">static</span> <span style="color:#800000; font-weight:bold; ">void</span> test_DBSCANVisitor<span style="color:#808030; ">(</span><span style="color:#808030; ">)</span>  <span style="color:#800080; ">{</span></span>
<span class="line_wrapper"></span>
<span class="line_wrapper">    <span style="color:#666616; ">std</span><span style="color:#800080; ">::</span><span style="color:#603000; ">cout</span> <span style="color:#808030; ">&lt;</span><span style="color:#808030; ">&lt;</span> <span style="color:#800000; ">"</span><span style="color:#0f69ff; ">\n</span><span style="color:#0000e6; ">Testing DBSCANVisitor{ } ...</span><span style="color:#800000; ">"</span> <span style="color:#808030; ">&lt;</span><span style="color:#808030; ">&lt;</span> <span style="color:#666616; ">std</span><span style="color:#800080; ">::</span><span style="color:#603000; ">endl</span><span style="color:#800080; ">;</span></span>
<span class="line_wrapper"></span>
<span class="line_wrapper">    <span style="color:#800000; font-weight:bold; ">typedef</span> StdDataFrame64<span style="color:#800080; ">&lt;</span><span style="color:#666616; ">std</span><span style="color:#800080; ">::</span><span style="color:#603000; ">string</span><span style="color:#800080; ">&gt;</span> StrDataFrame<span style="color:#800080; ">;</span></span>
<span class="line_wrapper"></span>
<span class="line_wrapper">    StrDataFrame    df<span style="color:#800080; ">;</span></span>
<span class="line_wrapper"></span>
<span class="line_wrapper">    <span style="color:#800000; font-weight:bold; ">try</span>  <span style="color:#800080; ">{</span></span>
<span class="line_wrapper">        df<span style="color:#808030; ">.</span><span style="color:#603000; ">read</span><span style="color:#808030; ">(</span><span style="color:#800000; ">"</span><span style="color:#0000e6; ">SHORT_IBM.csv</span><span style="color:#800000; ">"</span><span style="color:#808030; ">,</span> io_format<span style="color:#800080; ">::</span>csv2<span style="color:#808030; ">)</span><span style="color:#800080; ">;</span></span>
<span class="line_wrapper">    <span style="color:#800080; ">}</span></span>
<span class="line_wrapper">    <span style="color:#800000; font-weight:bold; ">catch</span> <span style="color:#808030; ">(</span><span style="color:#800000; font-weight:bold; ">const</span> DataFrameError <span style="color:#808030; ">&amp;</span>ex<span style="color:#808030; ">)</span>  <span style="color:#800080; ">{</span></span>
<span class="line_wrapper">        <span style="color:#666616; ">std</span><span style="color:#800080; ">::</span><span style="color:#603000; ">cout</span> <span style="color:#808030; ">&lt;</span><span style="color:#808030; ">&lt;</span> ex<span style="color:#808030; ">.</span>what<span style="color:#808030; ">(</span><span style="color:#808030; ">)</span> <span style="color:#808030; ">&lt;</span><span style="color:#808030; ">&lt;</span> <span style="color:#666616; ">std</span><span style="color:#800080; ">::</span><span style="color:#603000; ">endl</span><span style="color:#800080; ">;</span></span>
<span class="line_wrapper">    <span style="color:#800080; ">}</span></span>
<span class="line_wrapper"></span>
<span class="line_wrapper">    <span style="color:#800000; font-weight:bold; ">auto</span>    lbd <span style="color:#808030; ">=</span> <span style="color:#808030; ">[</span><span style="color:#808030; ">]</span><span style="color:#808030; ">(</span><span style="color:#800000; font-weight:bold; ">const</span> <span style="color:#666616; ">std</span><span style="color:#800080; ">::</span><span style="color:#603000; ">string</span> <span style="color:#808030; ">&amp;</span><span style="color:#808030; ">,</span> <span style="color:#800000; font-weight:bold; ">const</span> <span style="color:#800000; font-weight:bold; ">double</span> <span style="color:#808030; ">&amp;</span><span style="color:#808030; ">)</span> <span style="color:#808030; ">-</span><span style="color:#808030; ">&gt;</span> <span style="color:#800000; font-weight:bold; ">bool</span> <span style="color:#800080; ">{</span> <span style="color:#800000; font-weight:bold; ">return</span> <span style="color:#808030; ">(</span><span style="color:#800000; font-weight:bold; ">true</span><span style="color:#808030; ">)</span><span style="color:#800080; ">;</span> <span style="color:#800080; ">}</span><span style="color:#800080; ">;</span></span>
<span class="line_wrapper">    <span style="color:#800000; font-weight:bold; ">auto</span>    view <span style="color:#808030; ">=</span> df<span style="color:#808030; ">.</span>get_view_by_sel<span style="color:#800080; ">&lt;</span><span style="color:#800000; font-weight:bold; ">double</span><span style="color:#808030; ">,</span> <span style="color:#800000; font-weight:bold; ">decltype</span><span style="color:#808030; ">(</span>lbd<span style="color:#808030; ">)</span><span style="color:#808030; ">,</span> <span style="color:#800000; font-weight:bold; ">double</span><span style="color:#808030; ">,</span> <span style="color:#800000; font-weight:bold; ">long</span><span style="color:#800080; ">&gt;</span><span style="color:#808030; ">(</span><span style="color:#800000; ">"</span><span style="color:#0000e6; ">IBM_Open</span><span style="color:#800000; ">"</span><span style="color:#808030; ">,</span> lbd<span style="color:#808030; ">)</span><span style="color:#800080; ">;</span></span>
<span class="line_wrapper"></span>
<span class="line_wrapper">    DBSCANVisitor<span style="color:#800080; ">&lt;</span><span style="color:#800000; font-weight:bold; ">double</span><span style="color:#808030; ">,</span> <span style="color:#666616; ">std</span><span style="color:#800080; ">::</span><span style="color:#603000; ">string</span><span style="color:#808030; ">,</span> <span style="color:#008c00; ">64</span><span style="color:#800080; ">&gt;</span>  dbscan<span style="color:#808030; ">(</span><span style="color:#008c00; ">10</span><span style="color:#808030; ">,</span></span>
<span class="line_wrapper">                                                   <span style="color:#008c00; ">4</span><span style="color:#808030; ">,</span></span>
<span class="line_wrapper">                                                   <span style="color:#808030; ">[</span><span style="color:#808030; ">]</span><span style="color:#808030; ">(</span><span style="color:#800000; font-weight:bold; ">const</span> <span style="color:#800000; font-weight:bold; ">double</span> <span style="color:#808030; ">&amp;</span>x<span style="color:#808030; ">,</span> <span style="color:#800000; font-weight:bold; ">const</span> <span style="color:#800000; font-weight:bold; ">double</span> <span style="color:#808030; ">&amp;</span>y<span style="color:#808030; ">)</span>  <span style="color:#800080; ">{</span></span>
<span class="line_wrapper">                                                       <span style="color:#800000; font-weight:bold; ">return</span> <span style="color:#808030; ">(</span><span style="color:#666616; ">std</span><span style="color:#800080; ">::</span><span style="color:#603000; ">fabs</span><span style="color:#808030; ">(</span>x <span style="color:#808030; ">-</span> y<span style="color:#808030; ">)</span><span style="color:#808030; ">)</span><span style="color:#800080; ">;</span></span>
<span class="line_wrapper">                                                   <span style="color:#800080; ">}</span><span style="color:#808030; ">)</span><span style="color:#800080; ">;</span></span>
<span class="line_wrapper"></span>
<span class="line_wrapper">    view<span style="color:#808030; ">.</span>single_act_visit<span style="color:#800080; ">&lt;</span><span style="color:#800000; font-weight:bold; ">double</span><span style="color:#800080; ">&gt;</span><span style="color:#808030; ">(</span><span style="color:#800000; ">"</span><span style="color:#0000e6; ">IBM_Close</span><span style="color:#800000; ">"</span><span style="color:#808030; ">,</span> dbscan<span style="color:#808030; ">)</span><span style="color:#800080; ">;</span></span>
<span class="line_wrapper"></span>
<span class="line_wrapper">    assert<span style="color:#808030; ">(</span>dbscan<span style="color:#808030; ">.</span>get_noisey_idxs<span style="color:#808030; ">(</span><span style="color:#808030; ">)</span><span style="color:#808030; ">.</span>size<span style="color:#808030; ">(</span><span style="color:#808030; ">)</span> <span style="color:#808030; ">=</span><span style="color:#808030; ">=</span> <span style="color:#008c00; ">2</span><span style="color:#808030; ">)</span><span style="color:#800080; ">;</span></span>
<span class="line_wrapper">    assert<span style="color:#808030; ">(</span>dbscan<span style="color:#808030; ">.</span>get_noisey_idxs<span style="color:#808030; ">(</span><span style="color:#808030; ">)</span><span style="color:#808030; ">[</span><span style="color:#008c00; ">0</span><span style="color:#808030; ">]</span> <span style="color:#808030; ">=</span><span style="color:#808030; ">=</span> <span style="color:#008c00; ">1564</span><span style="color:#808030; ">)</span><span style="color:#800080; ">;</span></span>
<span class="line_wrapper">    assert<span style="color:#808030; ">(</span>dbscan<span style="color:#808030; ">.</span>get_noisey_idxs<span style="color:#808030; ">(</span><span style="color:#808030; ">)</span><span style="color:#808030; ">[</span><span style="color:#008c00; ">1</span><span style="color:#808030; ">]</span> <span style="color:#808030; ">=</span><span style="color:#808030; ">=</span> <span style="color:#008c00; ">1565</span><span style="color:#808030; ">)</span><span style="color:#800080; ">;</span></span>
<span class="line_wrapper"></span>
<span class="line_wrapper">    assert<span style="color:#808030; ">(</span>dbscan<span style="color:#808030; ">.</span>get_result<span style="color:#808030; ">(</span><span style="color:#808030; ">)</span><span style="color:#808030; ">.</span>size<span style="color:#808030; ">(</span><span style="color:#808030; ">)</span> <span style="color:#808030; ">=</span><span style="color:#808030; ">=</span> <span style="color:#008c00; ">19</span><span style="color:#808030; ">)</span><span style="color:#800080; ">;</span></span>
<span class="line_wrapper">    assert<span style="color:#808030; ">(</span>dbscan<span style="color:#808030; ">.</span>get_result<span style="color:#808030; ">(</span><span style="color:#808030; ">)</span><span style="color:#808030; ">[</span><span style="color:#008c00; ">0</span><span style="color:#808030; ">]</span><span style="color:#808030; ">.</span>size<span style="color:#808030; ">(</span><span style="color:#808030; ">)</span> <span style="color:#808030; ">=</span><span style="color:#808030; ">=</span> <span style="color:#008c00; ">11</span><span style="color:#808030; ">)</span><span style="color:#800080; ">;</span></span>
<span class="line_wrapper">    assert<span style="color:#808030; ">(</span>dbscan<span style="color:#808030; ">.</span>get_result<span style="color:#808030; ">(</span><span style="color:#808030; ">)</span><span style="color:#808030; ">[</span><span style="color:#008c00; ">4</span><span style="color:#808030; ">]</span><span style="color:#808030; ">.</span>size<span style="color:#808030; ">(</span><span style="color:#808030; ">)</span> <span style="color:#808030; ">=</span><span style="color:#808030; ">=</span> <span style="color:#008c00; ">31</span><span style="color:#808030; ">)</span><span style="color:#800080; ">;</span></span>
<span class="line_wrapper">    assert<span style="color:#808030; ">(</span>dbscan<span style="color:#808030; ">.</span>get_result<span style="color:#808030; ">(</span><span style="color:#808030; ">)</span><span style="color:#808030; ">[</span><span style="color:#008c00; ">10</span><span style="color:#808030; ">]</span><span style="color:#808030; ">.</span>size<span style="color:#808030; ">(</span><span style="color:#808030; ">)</span> <span style="color:#808030; ">=</span><span style="color:#808030; ">=</span> <span style="color:#008c00; ">294</span><span style="color:#808030; ">)</span><span style="color:#800080; ">;</span></span>
<span class="line_wrapper">    assert<span style="color:#808030; ">(</span>dbscan<span style="color:#808030; ">.</span>get_result<span style="color:#808030; ">(</span><span style="color:#808030; ">)</span><span style="color:#808030; ">[</span><span style="color:#008c00; ">14</span><span style="color:#808030; ">]</span><span style="color:#808030; ">.</span>size<span style="color:#808030; ">(</span><span style="color:#808030; ">)</span> <span style="color:#808030; ">=</span><span style="color:#808030; ">=</span> <span style="color:#008c00; ">82</span><span style="color:#808030; ">)</span><span style="color:#800080; ">;</span></span>
<span class="line_wrapper">    assert<span style="color:#808030; ">(</span>dbscan<span style="color:#808030; ">.</span>get_result<span style="color:#808030; ">(</span><span style="color:#808030; ">)</span><span style="color:#808030; ">[</span><span style="color:#008c00; ">18</span><span style="color:#808030; ">]</span><span style="color:#808030; ">.</span>size<span style="color:#808030; ">(</span><span style="color:#808030; ">)</span> <span style="color:#808030; ">=</span><span style="color:#808030; ">=</span> <span style="color:#008c00; ">10</span><span style="color:#808030; ">)</span><span style="color:#800080; ">;</span></span>
<span class="line_wrapper">    assert<span style="color:#808030; ">(</span>dbscan<span style="color:#808030; ">.</span>get_result<span style="color:#808030; ">(</span><span style="color:#808030; ">)</span><span style="color:#808030; ">[</span><span style="color:#008c00; ">0</span><span style="color:#808030; ">]</span><span style="color:#808030; ">[</span><span style="color:#008c00; ">6</span><span style="color:#808030; ">]</span> <span style="color:#808030; ">=</span><span style="color:#808030; ">=</span> <span style="color:#008000; ">185.679993</span><span style="color:#808030; ">)</span><span style="color:#800080; ">;</span></span>
<span class="line_wrapper">    assert<span style="color:#808030; ">(</span>dbscan<span style="color:#808030; ">.</span>get_result<span style="color:#808030; ">(</span><span style="color:#808030; ">)</span><span style="color:#808030; ">[</span><span style="color:#008c00; ">4</span><span style="color:#808030; ">]</span><span style="color:#808030; ">[</span><span style="color:#008c00; ">18</span><span style="color:#808030; ">]</span> <span style="color:#808030; ">=</span><span style="color:#808030; ">=</span> <span style="color:#008000; ">167.330002</span><span style="color:#808030; ">)</span><span style="color:#800080; ">;</span></span>
<span class="line_wrapper">    assert<span style="color:#808030; ">(</span>dbscan<span style="color:#808030; ">.</span>get_result<span style="color:#808030; ">(</span><span style="color:#808030; ">)</span><span style="color:#808030; ">[</span><span style="color:#008c00; ">10</span><span style="color:#808030; ">]</span><span style="color:#808030; ">[</span><span style="color:#008c00; ">135</span><span style="color:#808030; ">]</span> <span style="color:#808030; ">=</span><span style="color:#808030; ">=</span> <span style="color:#008000; ">145.160004</span><span style="color:#808030; ">)</span><span style="color:#800080; ">;</span></span>
<span class="line_wrapper">    assert<span style="color:#808030; ">(</span>dbscan<span style="color:#808030; ">.</span>get_result<span style="color:#808030; ">(</span><span style="color:#808030; ">)</span><span style="color:#808030; ">[</span><span style="color:#008c00; ">18</span><span style="color:#808030; ">]</span><span style="color:#808030; ">[</span><span style="color:#008c00; ">3</span><span style="color:#808030; ">]</span> <span style="color:#808030; ">=</span><span style="color:#808030; ">=</span> <span style="color:#008000; ">103.550003</span><span style="color:#808030; ">)</span><span style="color:#800080; ">;</span></span>
<span class="line_wrapper"><span style="color:#800080; ">}</span></span>
<span class="line_wrapper"></span></pre>

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